The present invention provides a method and apparatus for determining the presence and quantity of biological and/or chemical analytes using a deflectable arm of a microcantilever that is at least partially embedded within a sensing material formed on a surface. The sensing material is chosen to undergo a volumetric expansion or contraction in response to the presence of an analyte or analytes desired to be detected. A volumetric change, with a component in a vertical direction of the sensing material causes the embedded portion of the arm to move vertically and places a measurable strain on the arm. The microcantilever arm includes at least one measurable physical property which changes when stress is applies to the arm. This change is measured to determine the presence and quantity of the analyte or analytes of interest.